Universal thread gauge



Marci; 6, 1928.

2 Shee1;s Sheet '1.

Marchxg, 1928.

c. J. SCHEN UNIVERSAL THREAD GAUGE Filed June 21. 1924 2 Sheets- Sheet 2 Patented Mar. 6, 1928.

UNITED STATES CHARLES J, SCHEN, OF DETROIT, MICHIGAN.

UNIVERSAL THREAD GAUGE.

Application filed June 21, 1924. Serial No. 721,428.

versal thread gauge that is simple in con;

struction, easily and efficiently operated and can be manufactured at a low cost. I

These several objects are attained by th construction and arrangement of parts more fully hereinafter set forth.

Similar parts on all drawings are marked by similar numerals.

Fig. 1, shows a general view of the thread gauge and compensating means for determining the error when the gauge is adjusted to various size thread.

Fig. 2, is a side view of the gauge showing the mounting of the lower compensating levers.

Fig. 3, is a top view of the gauge.

Fig. 4, is an enlarged view of thevcompensating vernier. (Fig. 12 is the top View of Fig. 4.)

Fig. 5, is a detail of the extension bar for measuring pieces of larger diameter.

Fig. 6, is a detail of the thread block, changeable for various sizes of threads upon which the gauge is to be used.

Fig. 7, is a sectional view on the line -AA- on Fig.3, showing the general arrangement and the detailed construction of the gauge, and the interior means for extension of the gauge. j

Fig. '8, shows the gauge when opened, or extended. 7

Fig. 9,"is a cross section on line BB- of Fig. 7, showing the detailed arrangement of the compensating mechanism.

Flg. 10, 1s a cross section on line -CC-- I of Fig. 7 showing the coil spring for bolding the extension member in position.

Fig. 11, is a cross section on the line- -DD- of Fig. 7, showing the cam extension block for elongating the gauge frame. I will now describe more fully the de of connectingthreaded members, as to elongate the body of the gauge as the thimble is rotated. The micrometer sleeve carries a single thread engaging member mounted thereon, and the tubular body section is provided with double compensating thread engaging members pivotally mounted therein, and means for adjusting, and correcting error,-as the gauge members, are adjusted to various sizes of threads.

It is apparent that thegauge illustrated in the drawing is adapted for measuring diameters of internal threaded parts only, same being known as an internal thread gauge, and is used for measuring pitch diameters of threads, as illustrated in Fig. 1.

The body member -1is made of a solid piece of metal, formed int-o cylindrical section -2- and rectangular shaped section 51-.

other end thereof for retaining the adjust- The cylindrical drum2is formed I for recelvmg a rotatable mlcrometer sleeve 8 and a slotted end frame -3-- on the 5 able thread engaging members therein. The

body drum 2 isturned to atrue cylinceiwlng the adjusting micrometer screw -15. Along the top edge of the drum 2 are formed two extension cams 5, same being a part of drum '2, arranged on opposite sides of the recess 4. The

lower end of the drum section 2 is provided with an annular recess 6 for receiving: and retaining a coil compression spring 7 therein. The extension cams 5 are formed of helical curved surfaces (a) having fiat parallel tables (6) at each end thereof, as shown in Fig. 11, said flattables drical shape, and isprovided with a tubular recess 4. inthe top end thereof for recovering an angle to allow the micrometer sleeve 8 to rotate thereonninety degrees. Over the body of the drum '-2 is fitted a hollow cylindrical micrometer sleeve 8--,

for tightening said collar '-11 havingone open end therein, and tree to slide or move thereon. The sleeve 8- fitting and resting on the drum collar -o-,

inc-loses the entire drum- 2- therein. Near the open end of the sleeve 8 is an internal annular groove 9 for receiving the end of the conical coil spring -T-. At the closed end ofthe sleeve --S'- are two exteuleft about the axis thereof, over the drum -2-. the extension pins '--10 are raised by. the helical. cams andextend the sleeve 8'- beyond the body of the drum -'2-,- a distance equal to theheight oi the cum engaging the upper earntahles band held fiianly thereon hy the action of the spring -7-, thus increasing the capa'eity of the gauge. The center of the closed end of sleeve -S 's provided with a tapered threaded collar 11- and lock nut 12- on the in closed screw Along the outer face of the sleeve 8--, are scale gradnations 13. Over the sleeve 8 is titted the cylindrical micrometer thimhle -l4-, and rotatable thereon.

The thimble -1 t is closed at one end and provided with a: fixedly attached center adjusting screw 15-, for engaging the; threaded collar -1.1. of the inner sleeve -8-, and which moves the thimhle -14,- longitudinally on the sleeve -.8 asit is-rotated thereon. The. edge of the open end of the thimhle -1%t is graduated in equal spaces -1t3-, and h) determining the lead oi the threaded screw 15- and proper graduations of -1G, very accurate measurements may be deter mined. In the slotted end frame "3 ot the body l-, are mounted two L-shaped compensating arms -17, free to turn on pivots 18-, and having the inner. arm slotted at the end thereof; On both the outer sides of the frame -3-, are slots 19--, carrying a movable compensating slide -Qtl therein. Clhese slides 20- are connected by the pin 21-, extending across thenend slot in the end frame 3:-, and said pin engages-the slotted endsot the arms -1T in such ainnnner that any movement of the arms ,17' causes the slide EO-a to move longitudinally in the slots -19 Tire/slide -'QO carries graduahensw inscribed thereon, and corresponding gr'adnations -c are placed along the edge of the slide groove 19, for indieating the error allowable as th'e'arms -17- vtive thread grooves.

are adjusted to engage the dillercnt sizes of threads. To the outer ends of the arms l7- are attached the blocks --2:2, which are forlned with a small threaded shank e to engage the threads in arm --17-, and carry a small hall --ffor engaging the walls of the thread, as illustrated in Fig. l. ALso asingle hlock 22- is attached to the end of screw -1.'T and project-ing from the closed end of the micrometer tl'iinihle -l l-. The size of the halls fis predetern'iined for the ditl'erent size of threads to be measured, each size being made in sets of three, and tabulated for use with the diti'ercnt size threads. A further adjustment is madcin the gauge by use of the extension har -23-.lfiig. I, which is made in one hall inch lengths, or some multiple thereof, and is attached to the gauge member in place of the thread block 22, and then the. thread lilocl; -:22-- screwed therein for the purpo:;e of extending the length of the gauge hod'y, increasing: its capacity for larger work.

As the. gange'is applied in measuring: in ternal thread diameters, the movable thread engaging arms -17- swing on pivots -18-, allowing the thread hall to engage two threads, as illustrated in Fig. l. \Vhen the halls arehrought together, and away from their parallel or zero Josition, thereby shortening the total lengti of the gauge, causingan error inpthe thimhlo micrometer reading on scale --lfl----. the total error is indicatedhy the reading on the com- 'iensating slide 20..- It can readily be seen that liy predetermined diametersntth'o halls for \th rious size threads, the properly graduated compensating slide and the main graduated thimhle reading, the exact pitch diameter of the threads can be determined.

Having fully descrihcd my universal thread gauge, what claim as my invention and desire to secure by Letters Patent is:

1. An inside, gauge comprising a cylindrical body, a eircumferentially graduated thimhle mounted thereon; means whereby said thinihle may he moved longitmlinally thereon, asingle throadengaging memhcr attached to the end ot said thimhlc, and projecting therefrom, two thread engaging members pivotally attachedito the body, at. the opposite end, and pivot means for allowing adjustment of said two thread engaging members simultaneously'to engage consecu- 2. An insidegauge for measuring diameters of internally threaded apertures, comprising a cylindrical body, a rotatably mounted thimble, oircumferentially graduated, fitted over-said body, means whereby said thimblemaybe moved longitudinally thereon a single thread engaging member projecting from theend of the said thimble,

two thread engaging members pivotally mounted in the body at the opposite end to the thimble, pivot means for allowing adjustment of the two thread engaging members simultaneously to threads of the machine parts to be measured, and means fdr indicating the error in measurement caused by said thread adjustment.

3. An inside gauge adapted for measuring diameters of internally threaded apertures, comprising a cylindrical body, a thimble circumferentially graduated mounted thereon, means whereby said thimble may be moved longitudinally thereon, a single thread engaging member projecting from the end of said thimble, two thread engaging members attached to the opposite end,

of the body, said two members positioned parallel with each other and parallel with the axis of the body, and projecting therefrom, a graduated compensating slide attached to said body and connected to the two thread members and slide as they are adjusted to engage threads of the machine part to be measured.

4. An inside gauge adapted for measur ing diameters of internally threaded apen tures, comprising a cylindrical body having one end thereof slotted, and having a thimble circumferentially graduated 'zrotatably mounted on said cylindrical body, means whereby said thimble may be moved thereon longitudinally, a single fixed thread engaging member projecting from the end of said thimble, two thread engaging members pivoted in the slotted end of the drum body and projecting therefrom and parallel thereto,

said thread engaging members being formedv L-shaped and are slotted in the upper ends thereof for receiving a movable block pin, an exterior compensating slide mounted in the side of the slotted section ofthe body, and a block pin projecting therefrom for engaging the slotted. ends of the two thread engaging members.

5. An inside gauge adapted for measuring the diameter of internally threaded apertures, comprising a cylindrical body having one end thereof slotted, an extension sleeve movably mounted thereon, means for moving said sleeve longitudinally on said body, a thimble circumferentially graduated and rotatably mounted on the extension shoulder,

sleeve and having a threaded adjusting member fixedly attached to the end of the thimble, a single thread engaging member projecting from the end of the thimble, two L-shaped, slotted, threaded engaging members pivoted in the slotted end of the body, extending therefrom andparallel to the axis thereof, said L-shaped members being movable on the pivots for adjusting to threads of various sizes, an exterior graduated compensating slide mounted on the body connecting the slotted ends of the two L-shaped engaging members, and means for connecting said slide thereto.

6. An inside gauge adapted to measuring diameters of internally threaded apertures, comprising a cylindrical body having one end thereof slotted and provided with helical extension cams, a cylindrical extension sleeve movably mounted on said body, pins mounted in sleeve for preventing continuous rotation thereon, cam pins fixedly attached to the interior walls of the extension sleeve, projecting therefrom to engage the helical extension cams on the body, a coil spring annularly interposed between the walls of the movable extension sleeve and the body, said coil spring engaging the walls of both members and so positioned as to hold the extension sleeve to the body a circumferentially graduated thimble rotatably mounted on the extension sleeve and having a threaded adjusting member fixedly attached to the closed end of the thimble for engaging therewith, a ball tipped thread engaging member fixedly mounted on the end of said thimble and projecting therefrom, a pair of slotted L- shaped thread engaging members pivotally mounted in the slotted end of the body so positioned that the slotted ends thereof, overlap each other near the center of the slotted end of the body, ball tipped thread blocks attachedto the ends of the L-shaped thread engaging members, a compensating slide mounted in the'slotted end of. the body and connecting the slotted ends of the thread engaging arms, a slide pin for attaching the slide to the movable thread members.

In witness whereof I sign these specifications.

CHARLES J. SCHEN. 

